Dichloromalononitrile as an insecticide



Patented Sept. 26, 1944 DICIHDROMALONONITRILE ASAN INSECTICIDE IngenuinHechenbleikner, Stamford, Conn., as-

sisnor to American Gyanamid Company, New York, N. Y., a corporation ofMaine No Drawing. Application my 31, 1942,

Serial No. 453,037

1 Claim.

The present invention relates .to dichloromalononitrile as aninsecticide.

It has been discovered that dichloromalononitrile provides a new andeffective means for controlling insects, particularly those insects 5which infest grain, such as for example 7 the granary weevil, riceweevil, confused flour beetle and the like, and for the extermination ofsuch pests as roaches, bed bugs and carpetbeetles which frequentdwellings.

This new insecticidal agent is a colorless liquid having a boiling pointof 95-96 C. at 760 mm.

-It may be prepared by passing chlorine into malononitrile under refluxon a steam bath and then distilling under reduced pressure to recover 15the product. The chlorination proceeds slowly and may be hastened byadding a very small amount of iodine and irradiating the mixture withstrong artificial light.

When used as a iumigant, the compound either go alone or in admixturewith others may be applied, as for example, by atomizing or vaporizingwith or without heat into the enclosure a measured quantity of thematerial either at atmospheric pressure or at reduced air pressures. Thecompound, may also be introduced into the space to be fumisated in theform of impregnated solids such as kieselguhr or oellulosic board orother absorbent bodies carrying the compound. It may also be used in theform of solutions or:

emulsions from which it is subsequently vaporized.

The invention will be illustrated'in greater.

detail by the fumigation tests listed in the following table. The periodof e p sure is one hour for each test.

$81 1 l c oromaer een Insect lononitrile kill rim/1000 cu. ft.

Bloc weevils 20 70. 7 Do 40 99. 0 10 67. 9 20 100. 0 20 96. 0 30 100.0

Dichloromalononitrlle is a strong lachryrnator and hence serves warningas to spaces being fumigated therewith.

This compound'may be used alone or in admixture with other fumigants,insecticides or diluents, It has sufllciently low inflammability to besafely used as a fumigant.

While the invention has been described with particular reference tospecific embodiments it is to be understood that it is not to be-limitedthereto but is to be construed broadly and restricted solely by thescope of the appended claim.

What is claimed is:

A method of combating insects which includes applying thereto a toxicquantity of dichloromalononitrile. w

